Method of producing eaves-troughs



M. L. HUNKER. METHOD OF PRODUCING EAVES TROUGHS. APPLICATION HLED JUNEZI, L920.

1,3?7,251 Patented May 10,1921;

Hal.

WITNESSES- INXZENTUH- and even distributionor-flow thereof during the successive 'operations1s absolutely prevented,,resulting in the product on of a- UNIT-ED sr-A'rss PATENT OFFICE,

MARTIN L. BUNKER, or WHEELING, wnsrvmemm, ASSIGNOR To wn MAKER.

emassnnn COMPANY, A. CORPORATION or wEs'r vmemm,

uErrnon or-rnozoocrne na'vrsqmouens.

To all whom it may concern:

Be it known that I, MAn'rIN L. HUNKER, a citizen of the United. States of America, and resident of Wheeling, county of Ohio, and State of West Virginia, have invented certain new and useful Improvements in Methods of Producing, Eaves-Troughs, of which the following is a specification.

This invention relates to the manufacture of caves troughs and other sheet metal products of arcuate cross-sectional form, and it has for its object to provide'an improved method or "process of producing eaves troughs and the like whereby "the metal is gradually drawn or developed-in a succession of operations into an accurately curved trough shape, forming a product which is devoid of the distortions and irregularities appearing in such troughs "as lproduced by methods heretofore prevailing. v

Hitherto, in the production of caves troughs, it has been'the universal practice to shape the body of the trough by a sue-- cession of pressing or rolling operations.

during which the lateral edges of the blank, or the lateral rolls or beads where such were carried by the blank, have been rigidly held and in which'the entire body of the blank,

or that portion of the latter between the beads, has been at each successive operation received between and tightly gripped by the cooperating forming dies .orrolls. to the fact that, in'practising such 'method,

Due

, the lateral edge'sor beads are held rigidly'and that the upper and lower-dies or rolls seat in 'cobp'erative relation to the blank throughout the entire opposite surfaces of the latter I from the first to the last of the successive trough forming operations, as aforesaid, the metal of the blank is so confined that free trough which presents edges or .beads having an-irregularfundulatory, or wavy, form.

Various expedients'ihaving for their purpose to obvlatefor remedy this defect have been resorted .t o,,as, ffor instance, the provision of crim'pscorrugations, an les and like edge-stiffening formationsin e edges accurately regular curvature and having Specification of Letters Patent.

Patented May [10, 1921.-

Application filed June 21, 1920. Serial No. 390,401.

. perfectly straight, or non-sinuous, edges or beads.

In carrying out my invention, following the formation of the lateral beads, where the trough is to have such heads, the blank advanced successively between coiiperat-v mg forming dies which are arranged in' a plurality of sets and which are preferably of the rotarytype, although reciprocating d1es may also be employed for the purpose.

In order that the metal of theblank shall way between, the edgesof the blank and thence to'proceed progressively inopposite directions to or adjacent to sand edges, and

. the blank is at no time subjected to restraint at points lateral with respect to the median line in which the successive dies act to produce the requisite successive bends. Otherwise expressed, the sets of dies employed operate successively in areas of progressively ncreasing width and each confines against or restrains from fre e and unobstructed accommodating movement onlythe area upon which it directly operates. g

Another important feature of my invention, and one to which especial-attention is directed, consists in producing, 'a's' an initial step in the development ofthe trough, preliminary trough-shaping curves at points, or in areas, contiguous to the lateral edges of the blank, such curves being designed to .coincide with the curves produced in the final operation and facilitating-the"product1on of'a trough having perfect uniformity of curvature. This preliminary shaping is sential, to the production of caves troughs. having lateral beads, it beingpractically impossible to produce at a final step in the forming' operations the proper curvature directly contiguous to the bead without subjecting such head to distortion.

The accompanyingdrawings, Fi res 1 to 22, inclusive, illustrate the successive shapes imparted to the metal blank in following the different steps of my process for the development of .a trough.

As herein illustrated, it is designed that the finished product, depicted in Fig. 22, shall be an eaves trough the body 1 ofwhich '95 "especially important, if not positively es angle terminal flanges 4 along the lateral.

i has rolls or beads 2 provided with the usual angular flanges, or inner locks, 3; and while the description which follows contemplates the formation'of a head-on each of the lateral edges of'the trough, it will be understood that one; of said beads may be omitted, as

when alain edge is desired.

A pre erred form of mechanism or appa- I ratus for performing the steps of my process is shown in acompanion application, Serial No.390,4 02, but it will be understood that the process may be carried-out by other mechanisms or instrumentalities than the dies of roller type shown inlsaidapplication.

The process involves three ma or operations, performed in sequence as follows: First, the formation of marginal flanges disposed at right angles to theplane of the intermediate body portion of the blank. Second, the curling of said marginal flanges to form lateral rolls or beads. Third, the

bending of the beaded body into arcuately curved trough shape. Further, each of said major operations involves a succession of relatively graduated minor operations which constitute steps in which the blank, or portions'thereof, are progressively drawn or developed to produce the requisite shape.

The first operation performed on .the'plain' sheet is the formationof downturned rightedges of the sheet, as shown in Fig. 1, said flanges being offnarrow width and designed without further shaping to constitute the inner locks 3 of the finished product. The

second operation consists'in producing bends 5 in the blank at points located inward an appropriate distance from the terminal flanges .4 for forming. marginal flange portions 6 having very slight downward incli-- ture, indicated at 7, which is preserved throughout and appears in the finished product Foliowing'said second operation, the marginal flanges 6 are acted upon'in a succession of graduated operations for progressively increasing their angles of'inclination,

- as shown in Figs. 3 to '7, inclusive, until they are finally disposed at right angles to the ori inal plane.

he blank is next subjected to a series of relatively graduated operations in which the marginal flanges 6 are progressively curled, as shown in Figs. 8 to 16, inclusive, for producing the lateral rolls or beads 2 t0 be borne by the finished product.

The blank is next subjected to the shaping action of a series of dies which operate to develop the blank body 8, or that portion located between the. previously produced curves 7, from the approximately plane form shown in Figs. 2 to 16, inclusive, to the final semi-circular trough-shape shown in Fig. 22. This final development is accomplished gradually, and, in accordance with the present. invention, involves the employment of a series of sets of cooperating dies which successively operate upon the blank body in areas of progressively increasin width and each of which acts to grip on y so much of the area of said body as it directly operates upon, leaving the remainder of the body free to adjust or 'accom'odate itself to the stresses imposed upon or set up within the blank. While the lower, or female, dies of the trough-shaping series should conform to and substantially correspond. in width with that of the blank whichis passed thereover, each of the upper, or male, dies has a width no greater than is necessary to produce the depression of the metal to the extent desired. The blank body is initially acted upon by an upper die of extremely narrow width which produces a central longitudinal downwardly-pressed angular bend indicated at 9 in Fig. 17. Each succeeding upper die of the series is of relatively increased width and acts to depress the central portion of the blank body to a greater depth, so that the regular semi-circular form is approached gradually and progresses from the center or median line outwardly until the curvature produced by the last set of the series accuratel merges or. meets in accord with the previously produced curves 7.

Due'to the revision of the curves 7 at an initial operatlon in the development of the blank, it is rendered possible to produce contiguousto the beads the degree of curvature which is required to round out the trough into a uniformly curved semi-circular form and which, because of the resiliency of the metal of the blank, is not obtainable by the use of shaping dies in a final operation.

It wlll be articularly. noted that the development of the'final trough shape is performed by dies or rolls the peripheral or metal-shaping surfaces of which are produced on radii of progressively increasing length. Owing to the fact that the metal of the blankls acted upon first along its center line producing a curvature of small radius and isthence gradually developed by produced curvatures of progressively increasing radii, the natural tendency of the lateral portions of the metal is to spring nward, and not outward as is the case when the curvature is developed by heretofore prevailing methods. The result is that material of a resilient character is-readily developed .into true semi-circular shape which areas of relatively increasing-width and in;

which areas lateral unconfined. 2. The method of forming eaves troughs, which includes bending the stock 1nto trough shape by a succession of curving opto that acted upon are erations in which it is initiallyengaged and bent along its center line in anarea of small width and is then subjected tofafseries of complemental bends in areas of progressively increasing width and in which areas lateral to that acted upon are unconfined.

3.- The method of forming eaves troughs,

I which includes the formation. of lateral beads on asheet metal blank, depressing the.

body of the blank at an initial step in the bead-forming operations toform curves contiguous to the subsequently formed beads, and finally bending said body into trough shape by a-succession-of curving operations in which it is progressively developed from its center outward in o posite directions in areas of relatively increasing width. 7

4. The method of forming eaves troughs,

which includes the formation of lateral beads on a sheet metal blank, depressing the body of the blank-at an initial in'the bead-forming operations to form curves contiguous to the subsequently formed beads, and finally bendingsaid body into trough shape by a succession of curving operations in which it is progressively developed from its center outward in opposite directions in areas of relatively increasing width until the curvatureproduced meets and is supplemented by'the initially formed curves. I y I 5. The method of formingeaves troughs, which includes the beads on a sheet metal blank depressing the body of the blank at an initial step in the bead-formingoperations to form curves contiguous .to the subsequently formed beads,-

and finally bending said body into trough shape by a success'ionof curving operation gradually developed by a'successlon of sets in which'it is progressively developed from its center outward in opposite directions in areas of relatively increasing width while the portions of the blank located laterally of the areas acted upon remain unconfined;

6.v The method of forming eaves troughs,

which includes the; formation of lateral,

beads on a sheet metal blank, depressing the body of the blankat an initial step in the formation of lateral bead-forming operations to form curves contiguous to the subsequently formed beads, and finallybending said body into trough shape by a succession of curving operations in which it .is progressively developed from its center outward in opposite" directions in' areas of relatively increasing width until the curvature produced meets and is supplemented by the initially formed curves, the portions of the blank located laterally of the areas acted upon in the development of the body being unconfined operating sets of dies which act ,to develop said body' from its center outward in opp0-- site directions in areas of progressively increasing width, the blank being. confined against self-adjusting movement only in areas directly operated uponbysaid dies for forming bends.

8.,The method of forming eaves troughs, which includes .the formation of lateral beads on a sheet metal blank, depressing the body of the blank at an initialstep in'the bead-forming operations to form curves con- .tig'uous to the subsequently formed beads, and finally bending said body'into .trough shape by means of a series of successively operating sets of dies the metal shaping surfaces of which have radii of progressively increasing length.

- shape by means of a series of successively 9. The method of forming'eaves troughs,

which includes bending a sheet metal blank into trough shape by a series of successive operations in which it is initially acted upon along its median line by a die having a narrow blank-engaging surface and is then gradually developed by a succession of dies having blank-engaging surfaces of.progressively increasing width; 4

' 10. The method of forming eaves troughs, which includes bending a sheet metal blank into trough shape by a series of successive operationsin which it is initially acted upon along its median line by a male d e having a narrow blank-engaging surface and is then form and then gradually developing a trough shape by a succession of operations in which the depth of the channel is progressively increased and the walls of the blank at opposite sides of the angle produced 5 by the initial bending are simultaneously developed into arcuate form by a succession ofourving steps in which they are acted upon in' areas which progressively widen from said angle outward toward the edges 10 of the blank.

'12..The method of forming sheet metal products of arcuately curved cross-section, which includes bending a sheet metal blank into trough shape bya series of successive curving operations in which it is developed 35 outward in opposite lateral directions inareas of relatively increasing width and in which areas lateral to that acted upon are unconfined.

In testimony whereof I aflix my signature. 20

MARTIN L. HUNKER. 

